TNF and hyperlipidemia: Moreover, serum proinflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1β, may contribute to the association between PD and hyperlipidemia.[27] Similarly, we found increased total cholesterol level (as an independent predictor for the occurrence of PD) indicated the significance of cholesterol-lowering therapy for improvement of periodontal status in hemodialysis patients.